Re: Three phase conversion In Rush current Concern.

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "BRIAN FOLEY" <ka1bbg@xxxxxxxxxxx>

Hi, well my brother and i have built this type convertor for years, a bit of
carefull testing they work just fine. we built one for a lathe in the 1970's
and that machine has been sold 3 times and still runs every day. Ronk has
been building this type convertor for years. my brother built one for a
church mission who was 3 miles from 3 phase power, 200 hp runs an embossing
printing press very well. cul brian f.
----- Original Message -----
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Friday, September 29, 2006 6:23 PM
Subject: RE: Three phase conversion In Rush current Concern.


> Original poster: "Mark Dunn" <mdunn@xxxxxxxxxxxx>
>
>
> Jim:
>
> I have not been following this thread so pardon me if my comments are
> redundant.
>
> I believe that your "3 phase converter" is the type where you are using
> an idling motor(shown on your sketch) to allow one to drive a 3-phase
> motor.  It is my understanding that this type of circuit will
> temporarily run a 3-phase motor up to a point somewhat below its 3-phase
> rating.  It is also my understanding that the circuit
> loads(currents)will be seriously out of balance.  As a result, it is not
> uncommon to eventually burn up the motor(not the idling one) when this
> circuit is used.  Thus, I am not sure if it will drive your system the
> way you want since it is not really 3 phase power that you are
> developing.
>
> I had originally thought you were building something like a generator
> set where you were mechanically coupling a 1 phase motor to a 3-phase
> generator(motor), driving the 1 phase with 220VAC/1PH and thus actually
> generating 3-phase power from the 2nd motor/generator.  Obviously, this
> is not the case, but this method would produce true 3-phase power.
>
> You might consult www.3phasepower.org.  I believe they have extensive
> information on 1 phase to 3 phase conversion.
>
> Mark
>
>
>
>
>  >Original poster: "Jim Mora" <jmora@xxxxxxxxxxx>
>
>  >Hello All,
>
>  >Here is the schematic of my proposed three phase converter to power my
>  >>Raytheon 3 phase 24 KV DC power supply (I also have a generator in
>  >progress). The capacitors are mid-range based on other phase converters
>  >documentation and are subject to trail and error, to achieve balanced
>  >output.
>
>  >http://hot-streamer.com/temp/JimMora/3PhaseStaticIdlerMotor.pdf
>
>  >If anyone has experience in this arena I could use some help.
>
>  >The motor will run at ~3425 rpm which has the benefit of handling
>  >sudden change in current draw (think spark gap) and the disadvantage of
>  >inrush current to start it up.
>
>  >The motor will draw around 49 amp in static state load conditions. The
>  >>LR rating @ 240v is 290 amps, yikes. I have seen a few schematics of
>  >>"soft start" with triac's or SCR's.
>
>  >I think  my neighbors to the right will see a burnout as will their
>  >computers as we are a distance from the pig and the service wire is
>  >1950's # 4 I think. I have upgraded to 100 amp service. Beef connected
>  >to turkey at the Mast head.
>
>  >Any suggestions would be appreciated, I am a novice in poly phase, yet
>  >>know the complexities of a seeming simple circuit.
>
>  >Thanks Much,
>  >Jim Mora
>
>